Possible Complications of Atrial Fibrillation

Left untreated, atrial fibrillation puts you at risk for serious problems such as stroke or heart failure.


Because your atria cannot move the blood properly, it starts to pool and get stuck in the small corners and grooves of the heart. Once stuck, the blood can start to clot. With all the irregular contractions in your atria, these clots can break free and get pumped into the circulation.

If a clot reaches the brain, it can get lodged in one of the blood vessels and cut off the blood supply to that part of the brain. This is a stroke.

Rarely, these clots can also go to other parts of your body and cause other complications.

Heart Failure

If atrial fibrillation is not controlled, your heart can become weaker and you may develop heart failure.

Heart failure occurs when your heart has to work too hard to keep blood flowing throughout your body. As a result, extra fluid builds up. This fluid retention can cause swelling of your ankles and lower legs, or it can build up in your lungs resulting in breathing difficulties and extreme fatigue.

Other Complications

For some people, atrial fibrillation can cause great tiredness, weakness or breathing problems. Uncontrolled atrial fibrillation can also cause chest pain, dizziness and extreme fatigue. In the elderly, it can also cause bouts of confusion.

Although not life-threatening, these symptoms may limit your everyday activities and lower your quality of life.